Blocks 43, 44 Flashcards
18 month old boy with a normal development until 5 months of age. Gradual regression of developmental milestones like inabililty to sit without support, poor head control, and loss of a social smile. Enlarged spleen and liver, diminshed deep tendon reflexes in all limbs, hypotonia, cherry red macula.
Neimann-Pick disease
AR
Sphingomyelinase deficiency –> sphingomyelin accumulation within lysosomes (look like lipid laden foam cells)
An elevated creatinine kinase (CK) is highly suggestive of what underlying problem?
Myopathy
Due to direct myocyte damage and leakage of muscle enzymes into the circulation
Common causes of myopathy with elevated CK
Hypothyroidism
Muscular dystophies
Inflammatory muscle diseases
Medications like statins
Autoimmune diseases (polymyositis, dermatomyositis)
Muscle pain and stiffness in shoulder, neck, and pelvic girdle. Worse in the morning and with activity. Normal Creatinine Kinase
Polymyalgia rheumatica
What drug should be given to a patient with recurrent calcium oxalate stones?
Thiazides (hydrochlorothiazide)
They effectively increase calcium reabsorption from the nephron
34 y/o man with severe chest and abdominal pain then suffers a cardiac arrest with pulseless electrical activity, internal hemorrhage was the COD. Autopsy shows a defect in a large extracellular glycoprotein normally found in abundance in large blood vessels, periosteum, and zonular fibers of the lens and functions to form microfibrils by surrounding elastin.
Marfan Syndrome
Defect in Fibrillin-1 - a major component of microfibrils that form a sheath around elastin fibers.
Heart = aortic dilation, regurgitation, or dissection, mitral valve prolapse
What drug decreases intestinal absorption of cholesterol by inhibiting the neimann-pick C1-like 1 (NPC1L1) transporter protein, which transports dietary cholesterol from the brush border of the small intestine?
Ezetimibe
In a person with Cyanide poisoning, the use of amyl nitrite has what effect?
It oxidizes ferrous (Fe2+) in hemoglobin to ferric (Fe3+), generating methemoglobin which is incapable of carrying oxygen but has a high affinity for cyanide so it sequesters cyanide in the blood, freeing it from cytochrome oxidase and limiting it’s toxic effects.
Other than amyl nitrite, what substances can be used as antidotes for cyanide poisoning?
Hydroxycobalamin (vit B12 precursor)
Sodium thiosulfate
What step in Vitamin D metabolism is directly affected by being in the sun?
Conversion of 7-dehydrocholesterol to Cholecalciferol
Newborn with intracranial, gastrointestinal, cutaneous, umbilical, or surgical site bleeding. What is lacking?
Vitamin K
Babies should be given intramuscular vitamin K because there is low vit K at birth due to poor placental transfer, low content in breast milk, and a sterile gut.
Vit K is critical for carboxylation of clotting factors 2, 7, 9, 10
Child with spontaneous by painless lower GI bleeding. Tc-pertechnetate localizes ectopic gastric mucosa and it’s increased uptake is diagnostic for what?
Meckel Diverticulum
Failed obliteration of the vitelline (omphalomesenteric) duct
Colicky abdominal pain with currant jelly (strawberry jam appearance) stools.
Intussusception
(meckel diverticulum can lead to this)
A frontal lobe lesion on what side causes apathy and depression?
Left-sided frontal lobe
A frontal lobe lesion on what side causes disinhibited behavior?
Right-sided frontal lobe lesion
Femoral hernias are between what 3 structures?
Inferior to the inguinal ligament
Lateral to the pubic tubercle
Medial to the femoral vein
What is the most important environmental risk for pancreatic cancer?
Smoking
von Willebrand factor serves what 2 roles in hemostasis?
- Promotes platelet adhesion at sites of vascular injury by binding to and crosslinking platelet glycoproteins (primarily Gp 1b) with exposed collagen underneath damaged endothelium.
- Protective carrier protein for factor 8 that increases it’s plasma half-life
Langhans giant cells are characteristic of granulomatous conditions, including the caseating granulomas associated with Mycobacterium tuberculosis infections. The macrophages that form these giant cells are activated by what?
CD4+ Th1 Lymphocytes
Chronic antral inflammation leads to a decrease in the number of somatostatin-producing cells (delta cells). What will be the result?
Decreased Somatostatin
Uninhibited gastrin release
Increased hydrogen ion secretion by parietal cells
Duodenal ulceration and duodenal gastric metaplasia
What are the common side effects of ACE inhibitors?
Decreased GFR
Hyperkalemia
Cough
Angioedema (rare but life threatening)
What is the course of the ureters and what structures are near them?
Within retroperitoneum just anterior to the psoas muscles. Midway from the kidnes to the pelvic inlet, gonadal artery and vein cross over the anterior surface of the ureter.
The ureters gain access to the pelvis by crossing over the anterior surface of the common iliac artery near its bifurcation into the internal and external iliac arteries. At this point, the ureter lies medial to the ovarian vessels and anterior to the internal iliac artery.
MOA of combined hormonal contraceptive pills?
Suppress GnRH and pituitary gonadotropin secretion, inhibiting ovulation
Acute coronary syndrome occurs due to plaque rupture, which leads to superimposed thrombosis and vessel occlusion. The likelihood of plaque rupture largely depends on the mechanical strength of the fibrous cap. What characterizes low strength?
Thin-cap fibroatheromas have large necrotic core covered by a thin fibrous cap. Activated macrophages infiltrating the atheroma contribute to the breakdown of ECM by secreting metalloproteinases. Ongoing intimal inflammation can destabilize the mechanical integrity of the plaque through release of these metalloproteinases, resulting in plaque rupture and consequent acute coronary syndrome.
What is the MOA of Acyclovir?
Complete inhibition of the viral DNA polymerase
What is the most characteristic skeletal manifestation of primary hyperparathyroidism? How does it present?
Osteitis fibrous cystica
Bone pain, subperiosteal erosions affecting the phalanges of the hand and a salt and pepper skill, and brown tumor bone cysts.
What mutation leads to constitutive activation of the epidermal growth factor receptor pathway, promoting increased cell proliferation and growth?
Activating mutations of the KRAS gene
What is the difference between major depressive disorder and persistent depressive disorder?
Persistent = at least 2 years
Major = at least 2 weeks
Benign leukocytosis (>50,000) that occurs in response to an underlying condition. Leukocyte alkaline phosphatase levels are normal or increased. What is this reaction and what is found on peripheral blood smear?
Leukemoid Reaction
Smear = increased bands, early mature neutrophil precursors (myelocytes), granules (dohle bodies - basophilic oval inclusions in mature neutrophils)
